The past few decades have fostered the development of the environmental industry dedicated to minimizing the harm to the environment resulting from ordinary industrial activities. Both public and industry are increasingly aware of the harm caused by not taking steps to mitigate the effects of waste left in the environment. Simply not disposing of the waste environmentally and by the use of containment is extremely expensive.
In the case of the oil industry, waste build-up in tanks, settling ponds, and containment cellars cannot be simply left in tact, as if discarded. Not only would those structures represent a significant lost investment by virtue of the loss of their use, but corrosion and decay of those structures will eventually, even though slowly, produce the same effects as if the waste material had been discarded initially. The costs of site remediation is tremendous and will eventually, due to its magnitude of cost, end up as a social cost borne by the taxpayers.
Due to the production and use of hydrocarbon fuels in many countries a significant proportion of the waste problems are associated with hydrocarbon fuels. Since hydrocarbon constituents, especially the heavier components, may fall out of solution, significant buildup problems occur. These types of problems are particularly severe where the process conditions are such that the lighter less-viscous components are in a position to differentially leave the solution, or where the heavier components such as waxes are allowed to settle and become stuck together.
The nature and conditions under which hydrocarbons can collect and self-adhere are many and varied. Further complications are caused by other materials present in the environment where the hydrocarbon is collected. For example, in a refinery a hydrocarbon stream may be exposed to heavy metals which may accumulate along with the hydrocarbon. In oil fields, oil spillage about a well may collect with drilling mud in concrete cellars surrounding the well head. As can be seen, the presence of other materials can hamper disposal of the hydrocarbon waste for a number of reasons. Structurally the other materials can combine with the adhesive effect of the hydrocarbon to form a hard solid. Where the other materials predominate, the hydrocarbon can require bulk processing of a relatively larger mass of material to remove the same amount of hydrocarbon. In cases where other, relatively inert but structurally enhancing material is present, a hydrocarbon contaminated with heavy metals can inhibit the remediation process due to the hazards involved in physically separating the contaminated hydrocarbon even before the step of decontaminating the hydrocarbon takes place.
Another hurdle involves the physical mutation of the hydrocarbon mass into a form which is transportable. A highly viscous wax is not transportable with ordinary small diameter four or five inch lines using standard available vacuum trucks, most of which are usually capable of creating a vacuum of about twenty seven to twenty eight inches of water column. Where masses of hydrocarbon waste cannot be suctioned, personnel are usually required to manually separate the hydrocarbon material.
Having to place personnel in intimate physical contact with the hydrocarbon material can bring its own associated set of problems. Where the mass is relatively free of volatile components, significant amounts of physical exertion is required to break up the mass requiring expensive labor costs and downtime for equipment, tanks, etc.
In instances where the mass is laden with volatiles or hazardous materials, the procedures, personnel safety and protective equipment can significantly slow the removal process. Factors slowing the process include the daily decontamination of the personnel and equipment, the limitations of movement which the personnel are subject to with the heavy, bulky, cumbersome equipment, and the reduced exertion possible with the cumbersome equipment.
Further, the contaminated hydrocarbon mixture must be further disposed of, even after the personnel has collected it. In the case where it is contaminated, the high cost of processing may outweigh the high cost of hazardous waste disposal. The result is the utilization of valuable disposal space, a finite and costly resource. One of the main elements of cost of the decontamination process is the physical separation of the contaminated species from the non-contaminated species, to enable concentrated processing of the contaminated material in the most concentrated form possible.
If the initial transport of the hazardous material were coupled with the first step of separating the hazardous from the non-hazardous material, the eventual cost of de-contamination could be lessened, especially if the initial separation were not accompanied by a loss of concentration.
One of the further problems in removing contaminated hydrocarbons is related to the use of solvents to dissolve and make less viscous the hydrocarbon portion of the material, in order to facilitate the movement of the material, as through pipes and conduits by pumping. However, hydrocarbon solvents in order to actively dissolve the contaminated hydrocarbon must be of low molecular weight and therefore volatile. Working with volatile hydrocarbons represents an increase in the hazards rather than a decrease in the hazards. Moreover, the result, even if the solvent dissolution works, is a volume of hazardous material including a volume of water which may be from about three to five times the volume of the original contaminated mass. Further, the hazardous material rather than being more concentrated to facilitate further treatment is now more dilute. Thus an additional step must be performed to remove the solvent from both the hazardous material and the non-hazardous materials if any are present.
The removal of the solvent must be done in a way which will yield the return of the non-contaminated solvent. Such treatment usually involves a distillation tower. However, the introduction of a contaminated solid into a distillation tower will yield a bottoms product which is similarly difficult to remove, which will in effect begin the waste removal problem over again.
What is therefore needed is a method to cause hardened waxy waste to become sufficiently broken-up and non-viscous to enable its transport with ordinary pumping and vacuum apparatus, and which will not add significantly to the overall volume of the material to be removed. The method should not add to the steps necessary to de-contaminate the material to be removed to the extent necessary to eliminate or minimize the necessity for hazardous waste disposal space. The method, process and chemicals used should not add to the hazardous or cumbersome nature of the cleanup and removal operation.